//
//  Observer.h
//  观察者模式
//
//  Created by flannery on 2018/12/19.
//  Copyright © 2018年 flannery. All rights reserved.
//

#import <Foundation/Foundation.h>
@class Subject;

@interface Observer : NSObject
@property (nonatomic, strong) Subject *subject;
-(void)update;
@end

@interface BinaryObserver : Observer
-(instancetype)initWithSubject:(Subject*)subject;
@end

@interface OctalObserver : Observer
-(instancetype)initWithSubject:(Subject*)subject;
@end


@interface HexaObserver : Observer
-(instancetype)initWithSubject:(Subject*)subject;
@end
